Experimental Study On Soil Erosion Prevention And Cure With Conservation Tillage In Jilin Region

This paper studied on the action of protect cultivating for preventing the soil eroding ofnorth-east area and nutrition losing,and discussed the protecting mechanisms of the strawmulch combing with soil erosion theory by rainfall. The place of experimentation is on CaoJia village YongJi county JiLin Province(situatedof the middle part of Jilin Province),and most of the area is dry land farming.The gradients ofthe land vary from 2°to 25°.The paper calculated district rain intensity,rain drops kinetic energy and rainfall,etc.withapplying hydrology,water and soil conservation theories,had discussed and proved thefeasibility of the simulation rainfall;through the experiment of district,the effect of soilerosion,N/P content by gradient,straw mulch ratio and the relation of straw returning to thefield rate and soil erosion are researched.The conclusions show that rainfall is motivity of soil erosion,and rainwater is impregnantof dissoluble nutrition.The rate of straw returning to the field influences soil loss moreobviously than gradient.The higher rate of straw returning to the field, the less quantity of soillosing. Graingranule which contains 56.3% is the main state of P's stream sendout.It indicatesthat graingranule matter with stream moving (diameter≥0.45um)is the main carrier of Pmoving.The gradient mainly influences the P'loss quantity of full state and graingranulestate.The greater gradient, the greater P's losing quanlity of full state and graingranule state onthe condition of the same rate of straw returning to field.Graingranule is the main state of N'sstream sendout.Graingranule state is 54.6% of sendout in N.It indicates that graingranulematter with stream moving (diameter≥0.45um)is the main carrier of N moving, and N ofcorresponding is the main form of the loss N with the earth's surface stream.Straw returning tothe field can prevent from N's losing obviously with a smaller gradient(6°),and it is lessobviously with a bigger gradient(22°).Grdient influences N's losing quality of full state andgraingranule state.The greater gradient,the greater N's losing quality of full state andgraingranule state on the condition of the same rate of straw returning to the field.The research is a beneficial attempt about soil erosion prevention and cure with conservationtillage in Jilin region,and provides a certain basis for agriculture production and control no-pointsource agriculture pollution,and proved that it is feasibility for Jilin region to extendconservation tillage according to the region geographical environment,entironment and socialeconomic strength.